All mining operations require blasting at one stage or another. Blast hole drilling is used in mining where a hole is drilled into the surface rock, packed with explosives, and detonated. The aim of this technique is to induce cracks in the inner geology of the surrounding rock, making deeper mining possible.
The drilling of blast holes is traditionally used when the mine would like to explore the mineral composition or potential mineral yield of an area that is considered for future mining. Blast holes can be considered a fundamental step in the exploration process, but also as in the extraction of coal.
It has become a highly specialized area requiring the excellent technical skills of those involved. Good blasting techniques have a direct benefit to mining operations because well-designed blasts reduce risks associated with health and safety concerns and improve operations through efficient extraction and environmental management.
Whilst blasting provides an efficient way to make deeper mining possible, it is also a hazardous process.
Gases are produced or released during mining operations including drilling and blasting, by mining types of machinery such as diesel and gasoline motors, and by other means such as the decay of timbers, the after-effects of mine fires, and chemical processes like oxidation.
The air in mines, especially coal mines, can also be contaminated by the presence of other gases such as carbon monoxide, hydrogen sulfide, methane, and excess carbon dioxide. Due to being in a confined space these gases are not always able to disperse and can therefore build up in the mine, and due to their combustible, explosive, or toxic qualities, this is a serious issue. This is because there is an increased risk as the coal dust can explode as a direct result of the ignition of flammable gases such as methane or operation induced by either blasting, machinery, or faulty equipment.
Standards can help ensure blasting best practices are followed, reducing these risks.
BS EN 14797:2006 describes the requirements for venting devices used to protect enclosures against the major effects of internal explosions arising from the rapid burning of suspended dust, vapor, or gas contained within. It includes the requirements for the design, inspection, testing, marking, documentation, and packaging.
Water trough barriers are autonomous protective systems by reducing the effects of combustible dust and/or firedamp explosions in underground mines to a sufficient level of safety. They are used for preventing the propagation of explosions in roadways in underground coal mines. The purpose of water through barriers is to extinguish explosion flames in roadways in underground mines and in this way to limit the propagation of explosions. They are designed and arranged in such a way that explosions are prevented from spreading through dangerous chain reactions and incipient explosions do not become detonations.
BS EN 14591-2:2007 specifies the requirements for concentrated and distributed passive water through barriers, and quick-deploy water through barriers. It also specifies the requirements and test methods for water troughs which are used as components of the "water trough barrier" protective system for underground coal mines.
BS EN 60079-35-2:2012 details performance and other safety features of cap lights, including those with a point of connection for other equipment, not covered in IEC 60079-35-1, but which are important for the safety and working conditions of the user. It may also be applied to cap lights for use in mines not likely to be endangered by firedamp.
BS EN ISO 19296:2018 specifies the safety requirements for self-propelled mobile machines used in underground mining. It deals with hazards, hazardous situations, and hazardous events relevant to these machines when they are used as intended or under conditions of misuse reasonably foreseeable by the manufacturer.
Firedamp drainage is a technical process for selected gas removal, the purpose of which is to reduce the risks presented by inflammable gas and air mixtures. Firedamp drainage is therefore a measure for preventive explosion protection.
BS EN 14983:2007 specifies the requirements for equipment and protective systems for firedamp drainage at mines. It also contains requirements for the construction and monitoring of this equipment and protective systems.
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